The Prediction of Heat Storage Properties by the Study of Structural Effect on Organic Phase Change Materials

Hásl, Tomáš; Jiříček, Ivo

doi:10.1016/j.egypro.2014.01.186

Cited by 24 publications

(11 citation statements)

References 11 publications

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“…Organic compounds, salts hydrates, and eutectic mixtures are typically applied for latent thermal storage systems in this temperature range. Attractive organic compounds in this temperature range are some of the carboxylic acid [201][202][203][204], sugar alcohols [205,206], alkanes (paraffin) [207] and amides [18]. Binary and ternary mixtures of nitrate salts of alkali and alkaline metals, such as potassium, lithium and sodium are the main compounds used to produce eutectic mixtures working in the temperature range from 120 to 200°C, known as ionic liquids [208].…”

Section: Off-site Waste Heat Recoverymentioning

confidence: 99%

A review of the applications of phase change materials in cooling, heating and power generation in different temperature ranges

et al. 2018

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Latent heat thermal energy storage is an attractive technique as it can provide higher energy storage density than conventional heat energy storage systems and has the capability to store heat of fusion at a constant (or a near constant) temperature corresponding to the phase transition temperature of the phase change material (PCM). This paper provides a state-of-theart review on phase change materials (PCMs) and their applications for heating, cooling and electricity generation according to their working temperature ranges from (-20℃ to +200℃). Four working temperature ranges are considered in this review: 1) the low temperature range from (-20℃ to +5℃) where the PCMs are typically used for domestic and commercial refrigeration; 2) the medium low temperature range from (+5℃ to +40℃) where the PCMs are typically applied for heating and cooling applications in buildings; 3) the medium temperature range for solar based heating, hot water and electronic applications from (+40℃ to +80℃); and 4) the high temperature range from (+80℃ to +200℃) for absorption cooling, waste heat recovery and electricity generation. Different types of phase change materials applied to each temperature range are reviewed and discussed, in terms of the performance, heat transfer enhancement technique, environmental impact and economic analysis. The review shows that, energy saving of up to 12% can be achieved and a reduction of cooling load of up to 80% can be obtained by PCMs in the low to medium-low temperature range. PCM storage for heating applications can improve operation efficiency from 26% to 66%, depending on specific applications. Solar thermal direct steam generation (DSG) is the most common electricity generation application coupled with PCM storage systems in the high temperature range, due to the capability of PCMs to store and deliver energy at a given constant temperature. The recommendations for future research are also presented which provide insights about where the current research is heading and highlights the challenges that remain to be resolved.

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Section: Off-site Waste Heat Recoverymentioning

confidence: 99%

A review of the applications of phase change materials in cooling, heating and power generation in different temperature ranges

et al. 2018

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“…(2) is really recommended and only the values estimated in the second methodwill be confirmed in the next topic of this work. Melting points of ethers and esters proved to have a trend so far, see the work of Hasl and Jiricek, 2014 [47]. Similarly, the melting temperatures of alkanes within the carbon atomnumber range 8 -20 are slightly similar, which is most likely due to the similar intensity of the intermolecular forces in the crystal lattice.…”

Section: Table6 Published and Calculated Enthalpies For Octadecanol(mentioning

confidence: 79%

The Published Fusion Enthalpy and its Influence on Solubility Estimation for Alcohols

2019

International Journal of Advanced Research in Chemical Science

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This paper aims to compare two different methods of estimating enthalpy of fusion and identify the one which is closer to the already published value. The n-long chain alcohols such asn-octanol(C8), dodecanol(C12), tridecanol(C13), tetradecanol(C14), pentadecanol(C15), hexadecanol(C16), heptadecanol(C17), octadecanol(C18), nonadecanol(C19)and eicosanol(C20)were the systems used for testing the methods. The experimental or estimateddata was available in the literature, and comparisons enabled the determination of the relative deviations for the compounds studied. It was expected that the enthalpy of fusion could be well evaluated by using sublimation and vaporization enthalpy as well as with the use of liquid and solid enthalpies of formation for the compound. However, when the results were compared with the literature ones, it was found that there are problems with the data published (experimental or not) because of the high relative deviations presented. Then, the prediction of solid-liquid equilibrium (SLE)had errors due to the high inconsistencepresented by this thermophysical property specially for C14, C15, C16 and C18. Thefirst method, which used the liquid and solid enthalpy of formationcan be used without restrictions and the second one had a better estimative of fusion enthalpy justfor some of the alcohols tested.

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“…Contrary to other homologous series in which hydrogen bonding is not present or not significant, the crystallization and melting enthalpies of the monoamides decreased exponentially with increasing chain length (Figure B,D). Without the influence of other factors, the crystallization/melting enthalpy of hydrocarbons is expected to increase with the methylene chain length because of the corresponding increase in the van der Waals and electrostatic interactions . The measurable decline of the enthalpy of the monoamides with increasing chain length, therefore, is evidence of the influence of the decreasing hydrogen bond strength and, particularly, the increasing hydrogen bond distribution (see Section ) which results in increasing regions of heterogeneity in the crystalline solids.…”

Section: Resultsmentioning

confidence: 99%

“…Without the influence of other factors, the crystallization/melting enthalpy of hydrocarbons is expected to increase with the methylene chain length because of the corresponding increase in the van der Waals and electrostatic interactions. 37,38 The measurable decline of the enthalpy of the monoamides with increasing chain length, therefore, is evidence of the influence of the decreasing hydrogen bond strength and, particularly, the increasing hydrogen bond distribution (see Section 3.1) which results in increasing regions of heterogeneity in the crystalline solids. Typically, a decrease in the enthalpy of monoamides can be expected when incorporated with thermal conductivity enhancers due to reduced mass fraction to release latent heat during phase transition.…”

Section: Thermal Transition Behaviormentioning

confidence: 99%

Lipid‐derived monoamide as phase change energy storage materials

et al. 2019

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Summary One of the major shortcomings of current organic phase change materials (PCMs) is their relatively low melting points, typically below 80°C, which limits their integration into thermal energy storage (TES) systems. The present work was aimed at developing lipid‐derived PCMs with increased melting points which would be suitable for TES applications requiring higher melting points without compromising other key properties such as enthalpy. The introduction of an amide group into the structure of linear saturated fatty acids was used as a means to increase intermolecular interactions and therefore crystallization and melting points. A series of six linear monoamides with differing chain length and symmetry about the amide group were investigated for thermal stability, thermal transition, flow behavior, and crystal structure to establish the structure‐property relationships relevant to TES. The presence of the highly polar amide group in the aliphatic fatty acid–derived molecules resulted in notable improvement in performance compared with the analogous monofunctional molecules: Increases in melting points (79°C‐96°C) and high enthalpies of fusion (155‐201 J/g) were recorded. Fundamental relationships between structure, processing, and macroscopic physicochemical properties, never before elucidated, were revealed in the study. The study revealed a step‐like variation of macroscopic properties: a surprising outcome of the competition between intermolecular attractions, symmetry effects, and mass transfer limitations. The predictive structure‐function relationships established in this work will allow the straightforward engineering of monoamide architectures that can extend the range of organic PCMs and deliver thermal properties desirable for TES applications.

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The Prediction of Heat Storage Properties by the Study of Structural Effect on Organic Phase Change Materials

Cited by 24 publications

References 11 publications

A review of the applications of phase change materials in cooling, heating and power generation in different temperature ranges

A review of the applications of phase change materials in cooling, heating and power generation in different temperature ranges

The Published Fusion Enthalpy and its Influence on Solubility Estimation for Alcohols

Lipid‐derived monoamide as phase change energy storage materials

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